Trolling motors are commonly used on bass boats, pontoon boats, and other watercraft for fishing or for other operations which require a relatively high degree of maneuverability along shorelines or in other tight locations. Various types of trolling motor assemblies are known in the art. One common type of trolling motor is a single tube assembly comprising: an electric motor and propeller assembly secured on the lower end of an elongate tube or other column; a control head or other housing structure attached in fixed position on the upper end of the column; and an electrical cable extending through the column from the control head to the motor and propeller assembly for operating the motor. The single tube trolling motor will typically be either manually rotated or rotated by external mechanical means for steering the watercraft.
An example of another common type of trolling motor is a rotating tube assembly comprising: a control head or other housing structure having a fixed tube extending from the bottom thereof; a rotatable tube or other rotatable column having an upper end which is received in the control head and a lower end which projects from the lower end of the fixed column; an electric motor and propeller assembly secured on the lower end of the rotatable column; an electrical cable extending through the rotatable tube from the control head to the propulsion motor for operating the motor; and a steering motor and gear assembly provided in the control head for rotating the rotatable tube in order to turn the motor and propeller assembly for steering the watercraft.
Various types of mounting systems are known in the art for securing a trolling motor to the deck, transom, or other part of a watercraft. Some of these systems permit the trolling motor to deflect in some manner from its normal operating position in the event that the motor impacts an underwater obstruction. For example, U.S. Pat. No. 6,394,408 discloses a ball and socket-type mounting system which comprises: a hard, rotatable ball element having a central bore through which the column of the trolling motor is received; a gated housing which forms a socket wherein the ball element and the trolling motor column are held and are permitted to rotate; and a position indicator which assists the operator in manually returning the trolling motor to its correct operating position after a deflection occurs. The gated head is secured on the outer end of a pivotable, four bar motor mount. The position indicator consists of a thin, flat (i.e., cylindrical) surface provided around the exterior of the ball element and a corresponding flat surface provided around the interior of the socket. The mounting system of U.S. Pat. No. 6,394,408 allows the trolling motor to deflect in any direction necessary for absorbing direct head-on, reverse, or side impacts or for absorbing glancing blows. The entire disclosure of U.S. Pat. No. 6,394,408 is incorporated herein by reference.
Other types of impact absorbing mounting systems or techniques known or suggested in the art include: bracket assemblies which allow the trolling motor to deflect in only a single plane; using a spring or other shock absorbing member which extends from the motor mount and has a clamp at the outer end thereof which is secured on the trolling motor column; a split ball assembly having a compression spring between the two halves of the ball; and forming the trolling motor column itself from some type of flexible material.
Unfortunately, the impact absorbing mounting systems heretofore known in the art have significant shortcomings. Most are difficult to install. Many cannot be installed on existing trolling motors without disassembling the motor itself. Some do not include any type of automatic return mechanism and therefore require that the operator manually reposition the motor in the event that a deflection occurs. Flexible motor columns are more costly and difficult to produce, particularly to achieve the degree of strength, flexibility and resiliency desired, and cannot be used on all types trolling motors.
Systems which incorporate metal springs or similar devices to provide at least some degree of automatic return are typically more complex and costly and can be particularly difficult to install or replace. Metal spring systems are also disadvantageous because they can rust and corrode and are loud during operation. When functioning, they tend to squeak or rattle. In addition, spring systems typically act in one direction only, usually toward the boat, such that they provide no deflection side to side or forward of the boat. Some spring systems also require operator intervention to tighten or loosen friction knobs to obtain the “right” feel.